Multi-Segment Oblique Flying Wing Aircraft

ABSTRACT

A multi-segment oblique flying wing aircraft which has three distinct segments including two outer wing segments and a central wing segment. The central segment may be thicker in the vertical direction and adapted to hold pilots and passengers. The outer wing segments may be substantially thinner and may taper as they progress outboard from the wing center. The multi-segment oblique flying wing aircraft be adapted for rotating into a high speed flight configuration, or may be adapted for take-off and cruise at a constant angle. In an extreme flight case, the central wing segment may rotate to a local sweep of ninety degrees.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to U.S. Provisional Patent ApplicationNo. 63/078,903 to Veble Mikic et al., filed Sep. 16, 2020, which ishereby incorporated by reference in its entirety.

BACKGROUND Field of the Invention

The present invention relates to aircraft, and more particularly to anaircraft with a multi-segment oblique wing design.

Description of Related Art

In 1958, R. T. Jones suggested that aircraft with asymmetrically-swept(oblique) wings would offer many advantages at high transonic and lowsupersonic speeds. There have been technical challenges associated withall-wing oblique wing configurations, in that such configurations lackthe powerful stability and control contributions from traditional tails.

What is called for is an oblique wing aircraft which can supportsignificant cargo and passenger payloads, while maintaining stabilityduring high-speed flight.

SUMMARY OF THE INVENTION

A multi-segment oblique flying wing aircraft which has three distinctsegments including two outer wing segments and a central wing segment.The central segment may be thicker in the vertical direction and adaptedto hold pilots and passengers. The outer wing segments may besubstantially thinner and may taper as they progress outboard from thewing center. The multi-segment oblique flying wing aircraft be adaptedfor rotating into a high-speed flight configuration, or may be adaptedfor take-off and cruise at a constant angle. In an extreme flight case,the central wing segment may rotate to a local sweep of ninety degrees.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a view of a prior art aircraft with a rotatable wing.

FIG. 2 is a view of an oblique wing aircraft with a pivoting wing.

FIG. 3 is an illustration of a multi-segment oblique wing aircraftaccording to some embodiments of the present invention.

FIG. 4 is a drawing of a multi-segment oblique wing aircraft accordingto some embodiments of the present invention.

FIG. 5 illustrates coordinate systems for an oblique wing according tosome embodiments of the present invention.

FIG. 6 illustrates wing design aspects for an oblique wing according tosome embodiments of the present invention.

FIG. 7 is a view of an oblique wing in a take-off configurationaccording to some embodiments of the present invention.

FIG. 8 is a view of an oblique wing in a high-speed configurationaccording to some embodiments of the present invention.

FIG. 9 is a view of an oblique wing in a fully rotated configurationaccording to some embodiments of the present invention.

FIG. 10 is a view of an oblique wing in a configuration with the centersegment perpendicular to the airflow direction according to someembodiments of the present invention.

FIG. 11A is a perspective view of a fixed orientation multi-segmentoblique flying wing aircraft with an outboard auxiliary control surfaceaccording to some embodiments of the present invention.

FIG. 11B is a top view of a fixed orientation multi-segment obliqueflying wing aircraft with an outboard auxiliary control surfaceaccording to some embodiments of the present invention.

FIG. 11C is a side view of a fixed orientation multi-segment obliqueflying wing aircraft with an outboard auxiliary control surfaceaccording to some embodiments of the present invention.

FIG. 11D is a rear view of a fixed orientation multi-segment obliqueflying wing aircraft with an outboard auxiliary control surfaceaccording to some embodiments of the present invention.

FIG. 12A is a perspective view of a fixed orientation multi-segmentoblique flying wing aircraft with an inboard auxiliary control surfaceaccording to some embodiments of the present invention.

FIG. 12B is a top view of a fixed orientation multi-segment obliqueflying wing aircraft with an inboard auxiliary control surface accordingto some embodiments of the present invention.

FIG. 12C is a top view of a fixed orientation multi-segment obliqueflying wing aircraft with an inboard auxiliary control surface accordingto some embodiments of the present invention.

FIG. 12D is a rear view of a fixed orientation multi-segment obliqueflying wing aircraft with an inboard auxiliary control surface accordingto some embodiments of the present invention.

FIG. 13A is a perspective view of a fixed orientation multi-segmentoblique flying wing aircraft with a winglet auxiliary control surfaceaccording to some embodiments of the present invention.

FIG. 13B is a top view of a fixed orientation multi-segment obliqueflying wing aircraft with a winglet auxiliary control surface accordingto some embodiments of the present invention.

FIG. 13C is a side view of a fixed orientation multi-segment obliqueflying wing aircraft with a winglet auxiliary control surface accordingto some embodiments of the present invention.

FIG. 13D is a rear view of a fixed orientation multi-segment obliqueflying wing aircraft with a winglet auxiliary control surface accordingto some embodiments of the present invention.

FIG. 13E is a side view of a fixed orientation multi-segment obliqueflying wing aircraft with a winglet auxiliary control surface accordingto some embodiments of the present invention.

FIG. 13F is a top view of a fixed orientation multi-segment obliqueflying wing aircraft with a winglet auxiliary control surface accordingto some embodiments of the present invention.

DETAILED DESCRIPTION

High speed aircraft design requires balancing the design requirementsfor take-off and landing, and slower speed flight, with the design goalscentered around high-speed flight, especially in transonic andsupersonic speed regimes. Prior designs have included conventional,swept wing, aircraft, and oblique wing designs. An oblique wingarrangement distributes lift over about twice the wing length as aconventional swept wing of the same span and sweep, which provides areduction in the wave component of lift-dependent drag in the supersonicspeed regime by a factor of 4. For oblique flying wings of high aspectratio, the supersonic volumetric wave drag is also favorable. An obliqueflying wing can also prove to be a very efficient configuration in thehigh transonic speed regime.

FIG. 1 illustrates an aircraft with a traditional fuselage and a mainwing and a horizontal stabilizer that are pivotally attached at theircenters to the fuselage. This type of aircraft was viewed as havingadvantages over the prior swing-wing designs. The pivoting wing does notdisplace the center of lift relative to the center of mass of theaircraft. FIG. 2 illustrates an oblique flying wing having an elongatedwing and pivoting propulsion units. This design allows for the wing tobe perpendicular to the airflow direction for take-off, and for therotation of the wing at higher speeds.

In contrast to the aforementioned examples, a multi-segment oblique wingaircraft according to embodiments of the present invention uses a long,thick, center segment that allows for the placement of pilots andpassengers in the center segment, and may allow for the use of themulti-segment oblique wing aircraft as a high-speed commercial aircraft.In a certain sense, the center segment takes on the ferrying function ofa traditional fuselage without the drawbacks of a traditional fuselage.Further, the separation of the outer wing segments by the long centerwing segment during a highly swept high-speed flight provides excellentcontrol authority due to the possibility to place multiple trailing edgecontrol surfaces such that they can affect both the pitch and roll axeswhen their actions are properly combined. The outer wing segments aresignificantly thinner than the center wing segment.

In some embodiments of the present invention, as seen in FIGS. 3 and 4,a multi-segment oblique wing aircraft 100 includes a center wing segment110, a left wing segment 111, and a right wing segment 112. The centerwing segment 110 is substantially thicker in the Zb direction (asdefined below), and is thick enough to allow for passengers in apassenger area 118. A plurality of thrust units 114, 116, 118 may usepivoting pylons 113, 115, 117 which allow for thrusting in differentforward flight configurations. The rotation of the thruster units willchange the sweep of the oblique wing aircraft, both due to the change inthrust direction and also due to a rudder effect of the pylons. Theremay be further trimming and control surfaces and devices which assist inthe sweep change.

In some embodiments of the present invention, as seen in FIGS. 5-10, amulti-segment oblique wing aircraft 200 includes a center wing segment210, a left wing segment 212, and a right wing segment 211. The centersegment 210 has a leading edge 210 a and a trailing edge 210 b. Althoughthere may be variations along their lengths, the leading edge 210 a andthe trailing edge 210 b of the center segment 210 are substantiallyparallel. The center segment 210 may be substantially thicker than theother segments and may be adapted to contain pilots and passengers ofthe aircraft. Although illustrated without propulsion units shown, it isunderstood the multi-segment oblique wing aircraft 200 may be poweredsimilarly to the aircraft 100 discussed above. In some aspects, asdiscussed further below, the thrust units will be non-rotating thrustunits, and the aircraft is adapted to take-off and cruise at a constantwing position.

The left wing segment 212 has a leading edge 212 a and a trailing edge212 b. The left wing segment 212 tapers as it routes outboard from thecenter segment 210, in that the chord length lessens along the span ofthe wing segment. The left wing segment 212 may be substantially thinnerin the vertical direction Zb than the center segment 210. The right wingsegment 211 has a leading edge 211 a and a trailing edge 211 b. Theright wing segment 211 tapers as it routes outboard from the centersegment 210, in that the chord length lessens along the span of the wingsegment. The right wing segment 211 may be substantially thinner in thevertical direction Zb than the center segment 210.

FIG. 5 introduces coordinate systems which illustrate aspects of thesystem. A prevailing wind coordinate system 230 includes the prevalentairflow across the wing as a composite of Xw and Yw, with Xw being theairflow direction seen in forward flight directly into the wind. A bodycoordinate system 231 is set to remain constant with the body of thewing, with the Yb axis set approximately parallel to the compositeaverage direction of the leading edges 212 a, 211 a of the wings. The Zbaxis of the body coordinate system comes out of the view towards theviewer. A quarter chord coordinate system 232 sets Yl as parallel to thequarter chord tangent at that point, and Xl as perpendicular to thequarter chord at that point. The body coordinate system 231 remainsfixed with regard to the aircraft. The prevailing wind coordinate system230 is a product of the environment and is independent of the wing, andthe quarter chord coordinate system 232 a function of the wing designbut alters relative to which point on the wing is being referenced.

The multi-segment wing may be viewed as having a transition from theleft wing segment 212 to the center wing segment 210 at a reference line220, and as having a transition from the right wing segment 211 to thecenter wing segment 210 at a reference line 221. Within the referencelines 220, 221, the leading edge 210 a and the trailing edge 210 b ofthe center segment 210 are substantially parallel.

An aspect of the multi-segment wing aircraft 200 is that each of thesegments 210, 211, 212 may have their own critical Mach number. Thecritical Mach number is the ratio of speed of local wind to the speed ofsound at which drag increases due to compressibility effects, and is afunction of airfoil thickness, lift on the section, and the local sweepof the section. In the context of this application, sweep refers toquarter chord sweep. The goal is for all segments to have a similarcritical Mach number that is slightly larger than the design Mach numberof the vehicle. The center wing segment 210 is substantially thickerthan the outer wing segments 211, 212 and will require more sweep forthe same critical Mach number. The outer wing segments 211, 212 arethinner and will require less sweep for the same critical Mach number.FIG. 7 illustrates a take-off configuration wherein the leading edges ofthe wing segments are substantially perpendicular to the prevailingairflow. This may also be a low(er) speed flight configuration. Thisconfiguration maximizes the span length of the wing segments, which arepredominantly perpendicular to the airflow in this take-offconfiguration. In contrast, the center segment is swept at an angle fromthe airflow direction.

As seen in FIG. 8 in a high speed flight configuration, themulti-segment wing aircraft 200 has rotated relative to the airflowdirection. In this high speed flight configuration, all segments havemore sweep than in the take-off configuration. The center wing segmentis more swept relative to the airflow direction than the outer wingsegments. This asymmetric sweep between the center segment and the wingsegments allows for a thicker middle section, which is desired in orderto accommodate pilots, passengers, and other cargo. The higher sweep ofthe center segment reduces or eliminates the wave drag penaltyassociated with the increased thickness of the center segment.

FIG. 9 illustrates a most extreme case of rotation, wherein the quarterchord line of the center segment is parallel to the airstream. FIG. 10illustrates a configuration with the leading edge of the center segmentsubstantially perpendicular to the airflow direction.

In some aspects, the use of the center segment as a repository for thepilots, the passengers, and other items which have volume, allows thecenter section to function somewhat as a fuselage of the aircraft, butwithout the disadvantages of a standard fuselage, while retainingadvantages of an oblique wing. The thick center segment relative to thethickness of the wing segments may also be seen in that the relativethickness, defined as the ratio of the chord length to the segmentthickness, is larger for the center segment relative to the wingsegments. Although the wing segments may be thicker where they couple tothe center segment, the wings will get much thinner in a transitionregion, similarly as they alter sweep through a transition region. FIG.6 illustrates aspects of the oblique wing according to some embodimentsof the present invention. As noted above, the multi-segment wing may beviewed as having a transition from the left wing segment 212 to thecenter segment 210 at a reference line 220, and as having a transitionfrom the right wing segment 211 to the center segment 210 at a referenceline 221. Within the reference lines 220, 221, the leading edge 210 aand the trailing edge 210 b of the center segment 210 are substantiallyparallel. The center segment 210 has an extended portion between itsfirst end at reference line 220 and its second end at reference line221, and in this portion the leading and trailing edges of the centersegment are substantially parallel. The ratio of the chord length of thecenter segment to its span may be 1:4 in some aspects. In some aspects,the ratio of the chord length of the center segment to its span may bein the range of 1:3 to 1:5. In some aspects, the ratio of the chordlength of the center segment to its span may be in the range of 1:2.5 to1:4.5. In some aspects, the chord length of the center segment does notvary by more than 10% along the span of the center segment. In someaspects, the chord length of the center segment does not vary by morethan 15% along the span of the center segment. In some aspects, thechord length of the center segment does not vary by more than 5% alongthe span of the center segment. Minimizing variation of chord length inthe center section allows more or less uniform cross section of thecargo or passenger cabin, similar to the uniform cross section of atraditional passenger aircraft fuselage. The relatively constant airfoilcross section of the center section also simplifies the design of thepropulsor units by reducing spanwise variation in inflow conditions. Therelatively long and skinny configuration of the aircraft, where wingsegments and the central section provide a joint body with a sizeableaspect ratio of length to chord, reduces wave volumetric drag of theaircraft in the supersonic regime. Combined with the increasedthickness-to-chord ratio of the center segment, this range of chord andspan ratios affords a good balance between aerodynamic performance andpayload capacity. As can be seen in FIG. 8 in the high speed flightconfiguration, the center segment has significantly more sweep than thewing segments, which accommodates its higher critical Mach numberrelative to the wing segments, which have somewhat lower sweep in thehigh speed configuration. The difference in sweep between the centersegment and the wing segments matches the effective critical Mach numberof the segments.

Outboard of the center wing segment 210 there may be transition regionswhere the leading edge line of the center wing segment 210 transitionsto the leading edge of the outer wing segments 211, 212. At the firstend of the center wing segment 210 at reference line 220 the wing maytransition until a reference line 241 wherein the leading edge of theleft wing segment 212 becomes substantially linear. Within thetransition area the left wing segment may curve around its leading edgeto its outboard linear position. The left wing segment 212 may alsotaper down its chord length both within its transition area and continueto taper outboard of its transition area and out to the wingtip. At thesecond end of the center segment 210 at reference line 221 the wing maytransition until a reference line 240 wherein the trailing edge of theright wing segment 211 becomes substantially linear. Within thetransition area the right wing segment may curve around its trailingedge to its outboard linear position. The right wing segment 211 mayalso taper down its chord length both within its transition area andcontinue to taper outboard of its transition area and out to thewingtip. Both the left wing segment 212 and the right wing segment 211are substantially thinner than the center segment 210. Although theremay be variations along their lengths, the leading edge 210 a and thetrailing edge 210 b of the center segment 210 are substantiallyparallel. The leadings edge 210 a and the trailing edge 210 b of thecenter segment 210 is also swept considerably more than the leadingedges 211 a, 212 a of the wing segments 211, 212 outboard of thetransition areas.

The use of a long, thick, center segment allows for the placement ofpilots and passengers in the center segment, and may allow for the useof the multi-segment oblique wing aircraft as a high speed commercialaircraft. In a certain sense, the center segment takes on the ferryingfunction of a traditional fuselage without the drawbacks of atraditional fuselage. Further, the separation of the wings by the longcenter segment during a highly swept high speed flight providesexcellent control authority due to the possibility to place multipletrailing edge control surfaces such that they can affect both the pitchand roll axes when their actions are properly combined. In some aspects,the ratio of the span of the center segment relative to the span of eachwing is in the range of 1:1 to 3:1. The optimum ratio of thickness alongthe span will depend on the details of the aircraft requirements andmaterials, but should be designed to balance aerodynamic drag(particularly wave drag), structural weight, and payload or fuelrequirements; optimum thickness ratios are likely to fall in the statedrange. In some aspects, the average thickness of the center segmentrelative to the average thickness of the wings is in the range of 1.5:1to 20:1. In some aspects, the ratio of the relative thickness of thecenter segment to the relative thickness of the wings is in the range of1.5 to 10.

In an exemplary embodiment, the overall wingspan (lateral dimension ofthe aircraft with the center segment unswept) of the aircraft is 60 m,with a planform area of 240 m², with a planform aspect ratio(wingspan²/area) of 15. In this exemplary embodiment, the wing segmentlengths are 18 m, each with an area of 65 m², and the center segmentlength is 26 m. The center segment chord is 6 m, with the wing segmentroot chord of 6 m, the wing segment tip chord of 1.2 m, and the wingsegment mean chord of 3.6 m. The wing mean chord to body mean chordratio is 0.6, and wing segment taper ratio is 0.2. The wing segmentaspect ratio ((2*segment length)²/(2*segment area)) is 10. The effectiveparasitic drag ratio (the measure of how well the centersegment/fuselage bridges the wing segments to reduce overall drag)((overall span)²/(2*segment area)) is 28. In this exemplary embodiment,the forward wing segment ¼ chord sweep is −5 degrees in the take-offconfiguration, with the center segment ¼ chord sweep at 25 degrees, andthe rear wing segment ¼ chord sweep at 5 degrees.

In some aspects, the overall wingspan is in the range of 5 m to 200 m.In some aspects, the aircraft planform area is in the range of 1 m² to3000 m². In some aspects, the aircraft planform aspect ratio is in therange of 5 to 30. In some aspects, the wing segment length is in therange of 2 m to 50 m. In some aspects, the center segment length is inthe range of 2 m to 80 m. In some aspects, the center segment chord isin the range of 0.5 m to 30 m. In some aspects, the wing segment rootchord is in the range of 0.5 m to 30 m. In some aspects, the wingsegment tip chord is in the range of 0.1 m to 20 m. In some aspects, thewing segment mean chord is in the range of 0.3 m to 25 m. In someaspects, the wing mean chord to center segment mean chord ratio is inthe range of 0.1 to 1. In some aspects, the wing segment taper ratio isin the range of 0 to 1. In some aspects, the wing segment area is in therange of 0.2 m² to 1000 m². In some aspects, the effective parasiticdrag ratio is in the range of 10 to 50. In some aspects, forward wingsegment quarter chord sweep is in the range of −20 to 20 degrees in thetake-off configuration, with the center segment quarter chord sweep inthe range of 10 to 70 degrees, and the rear wing segment quarter chordsweep in the range of −20 to 20 degrees.

In some aspects, embodiments of the present invention may benefit fromadding more pitch authority than the flying wing alone, depending on thedetails of the control surface layout and wing planform design. In someaspects, the multi-segment oblique flying wing aircraft is adapted totake-off, land, and cruise in the same swept configuration/orientation.

In another embodiment of the present invention, as seen in FIGS. 11A-D,a multi-segment oblique wing aircraft 250 adapted for take-off, land,and cruise in the same swept configuration/orientation has a wing 258with a left outer wing segment 258 a, a center wing segment 258 b, and aright side outer wing segment 258 c, with their respective quarter chordlines 257 a, 257 b, 257 c. The oblique wing characteristics, and rangesof parameters, may be as discussed with regard to the earlier embodiment200, above. With the aircraft 250, which does not rotate after take-off,the forward wing, the sweep of the wing segments remains constant duringdifferent flight modes. The forward sweep of the leading outer wingsegment may be 25 degrees. In some aspects, the forward sweep of theleading outer wing segment may be in the range of 15 to 35 degrees. Insome aspects, the forward sweep of the leading outer wing segment may bein the range of 0 to 60 degrees. The rearward sweep of the trailingouter wing segment may be 35 degrees. In some aspects, the rearwardsweep of the trailing outer wing segment may be in the range of 25 to 45degrees. In some aspects, the rearward sweep of the trailing outer wingsegment may be in the range of 0 to 60 degrees. The sweep of the centerwing segment may be 50 degrees. In some aspects, the sweep of the centerwing segment may be in the range of 35 to 65 degrees. In some aspects,the sweep of the center wing segment may be in the range of 25 to 75degrees. The aircraft 250 may have a plurality of thrust elements, andmay have four thrust elements nacelles 254 a, 254 b, 254 c, 254 d,coupled to pylons 253 a, 253 b, 253 c, 253 d. The right outer wingsegment 258 c may have a winglet 252, and has an auxiliary pitch controlsurface 251 which extends from the winglet 252 to either the outboardpropulsor nacelle 254 d (as-drawn), or the outboard propulsor pylon 253d. Such an arrangement may reduce the structural weight of thestabilizing surface 253 d by forming multiple structural load paths, mayreduce the aerodynamic coupling between pitch control input and roll,and may delay stall of the right wingtip. The auxiliary control surface251 may include a controllable control surface along its trailing edge.In some aspects, the entire auxiliary control surface 251 may berotatable as a controllable control surface.

In some aspects, the propulsor pylons 253 a, 253 b, 253 c, 253 d may beof different geometries in order to increase or decrease thequarter-chord 257 d sweep of the auxiliary pitch control surface 251. Inan exemplary embodiment, the right most pylon 253 d may be extended toincrease the sweep of the pitch control surface 251. In some aspects,the thrust elements nacelles 254 a, 254 b, 254 c, 254 d may havedifferent geometries to account for non-uniform flow conditionsintroduced by the auxiliary pitch control surface 251.

In another embodiment of the present invention, as seen in FIGS. 12A-D,a multi-segment oblique wing aircraft 260 adapted for take-off, land,and cruise in the same swept configuration/orientation has a wing 268with a left outer wing segment 268 a, a center wing segment 268 b, and aright side outer wing segment 268 c, with their respective quarter chordlines 267 a, 267 b, 267 c. The oblique wing characteristics, and rangesof parameters, may be as discussed with regard to the earlier embodiment200, above. With the aircraft 260, which does not rotate after take-off,the forward wing, the sweep of the wing segments remains constant duringdifferent flight modes. The forward sweep of the leading outer wingsegment may be 25 degrees. In some aspects, the forward sweep of theleading outer wing segment may be in the range of 15 to 35 degrees. Insome aspects, the forward sweep of the leading outer wing segment may bein the range of 0 to 60 degrees. The rearward sweep of the trailingouter wing segment may be 35 degrees. In some aspects, the rearwardsweep of the trailing outer wing segment may be in the range of 25 to 45degrees. In some aspects, the rearward sweep of the trailing outer wingsegment may be in the range of 0 to 60 degrees. The sweep of the centerwing segment may be 50 degrees. In some aspects, the sweep of the centerwing segment may be in the range of 35 to 65 degrees. In some aspects,the sweep of the center wing segment may be in the range of 25 to 75degrees. The aircraft 260 may have a plurality of thrust elements, andmay have four thrust elements nacelles 264 a, 264 b, 264 c, 264 d,coupled to pylons 263 a, 263 b, 263 c, 263 d. The right outer wingsegment 268 c may have a winglet 262.

The aircraft 260 has an auxiliary pitch control surface 261 supported bytwo or more propulsor pylons 263 c, 263 d or propulsor nacelles(as-drawn) 264 c, 264 d. Such an arrangement reduces the structuralweight of the supporting structure for the auxiliary pitch controlsurface 261 by using the existing propulsor pylon structure. Thepropulsor pylons 263 a, 263 b, 263 c, 263 d and/or nacelles 264 a, 264b, 264 c, 264 d may have different geometries to position the auxiliarypitch control surface as desired, for example, to increase or decreasethe quarter-chord sweep 267 of the auxiliary pitch control surface 261,or to account for nonuniform propulsor inflow conditions. The auxiliarycontrol surface 261 may include a controllable control surface along itstrailing edge. In some aspects, the entire auxiliary control surface 261may be rotatable as a controllable control surface.

In some aspects, the multi-segment oblique flying wing aircraft mayinclude rudder-like yaw control surfaces 269 a, 269 b, 269 c, 269 d onpropulsor pylon surfaces. Whether or not the propulsor pylons includecontrol surfaces, the pylons generally may serve the function ofincreasing lateral directional stability as a vertical fin might in aconventional aircraft design.

In another embodiment of the present invention, as seen in FIGS. 13E-F,a multi-segment oblique wing aircraft 270 adapted for take-off, land,and cruise in the same swept configuration/orientation has a wing 278with a left outer wing segment 278 a, a center wing segment 278 b, and aright side outer wing segment 278 c, with their respective quarter chordlines 277 a, 277 b, 277 c. The oblique wing characteristics, and rangesof parameters, may be as discussed with regard to the earlier embodiment200, above. With the aircraft 270, which does not rotate after take-off,the sweep of the wing segments remains constant during different flightmodes. The forward sweep of the leading outer wing segment may be 25degrees. In some aspects, the forward sweep of the leading outer wingsegment may be in the range of 15 to 35 degrees. In some aspects, theforward sweep of the leading outer wing segment may be in the range of 0to 60 degrees. The rearward sweep of the trailing outer wing segment maybe 35 degrees. In some aspects, the rearward sweep of the trailing outerwing segment may be in the range of 25 to 45 degrees. In some aspects,the rearward sweep of the trailing outer wing segment may be in therange of 0 to 60 degrees. The sweep of the center wing segment may be 50degrees. In some aspects, the sweep of the center wing segment may be inthe range of 35 to 65 degrees. In some aspects, the sweep of the centerwing segment may be in the range of 25 to 75 degrees. The aircraft 270may have a plurality of thrust elements, and may have four thrustelements nacelles 274 a, 274 b, 274 c, 274 d, coupled to pylons 273 a,273 b, 273 c, 273 d.

The multi-segment oblique wing aircraft 270 has a C-shaped wingletdevice 271. The winglet device 271 comprises a generally verticalaerodynamic surface 273 connected to a generally horizontal aerodynamicsurface 272 with appropriate aerodynamic blends between the two surfacesand the wing structure. Such a winglet device may decrease induced dragand provide additional longitudinal and lateral stability for theoverall aircraft. Certain embodiments of the present invention mayinclude a horizontal surface 272 outfitted with an actuator in order toprovide auxiliary pitch control authority, and the vertical surface 273may be outfitted with a movable trailing edge structure 273 a to provideadditional yaw control authority.

As evident from the above description, a wide variety of embodiments maybe configured from the description given herein and additionaladvantages and modifications will readily occur to those skilled in theart. The invention in its broader aspects is, therefore, not limited tothe specific details and illustrative examples shown and described.Accordingly, departures from such details may be made without departingfrom the spirit or scope of the applicant's general invention.

What is claimed is:
 1. An aerial vehicle, said aerial vehicle comprisingan oblique flying wing, said oblique flying wing comprising: a centerwing segment, said center wing segment comprising a leading edge and atrailing edge, said leading edge and said trailing edge parallel within10 degrees along their length; a forward wing segment, said forward wingsegment coupled to a first end of said center segment, said forward wingsegment comprising a leading edge and a trailing edge, wherein thespanwise average of the quarter chord of said forward wing segment isswept more than 10 degrees differently than the spanwise average of thequarter chord of the center wing segment; and a rear wing segment, saidrear wing segment coupled to a second end of said center segment, saidrear wing segment comprising a leading edge and a trailing edge, whereinthe spanwise average of the quarter chord of said rear wing segment isswept more than 10 degrees differently than said spanwise average of thequarter chord of the center wing segment.
 2. The aerial vehicle of claim1 wherein said center wing segment is substantially thicker than saidforward wing segment and said rear wing segment.
 3. The aerial vehicleof claim 2 wherein said forward wing segment is forward swept in therange of 15 to 35 degrees, and wherein said middle wing segment is sweptin the range of 35 to 65 degrees, and wherein said rear wing segment isrearward swept in the range of 25 to 45 degrees, while in a cruiseconfiguration.
 4. The aerial vehicle of claim 2 wherein said forwardwing segment is forward swept in the range of 0 to 60 degrees, andwherein said middle wing segment is swept in the range of 25 to 75degrees, and wherein said rear wing segment is rearward swept in therange of 0 to 60 degrees, while in a cruise configuration.
 5. The aerialvehicle of claim 2 wherein the ratio of the relative thickness of thecenter wing segment to the relative thickness of the outer wing segmentsis in the range of 1.5 to
 10. 6. The aerial vehicle of claim 3 whereinthe ratio of the relative thickness of the center wing segment to therelative thickness of the outer wing segments is in the range of 1.5 to10.
 7. The aerial vehicle of claim 2 wherein said aerial vehicle furthercomprises: a plurality of pylons coupled to said oblique flying wing;and a plurality of thrust elements coupled to said pylons.
 8. The aerialvehicle of claim 6 wherein said aerial vehicle further comprises: aplurality of pylons coupled to said oblique flying wing; and a pluralityof thrust elements coupled to said pylons.
 9. The aerial vehicle ofclaim 8 wherein said thrust elements are rotationally coupled to saidoblique flying wing, such that said thrust elements can rotate from atake-off position to a cruise position.
 10. The aerial vehicle of claim7 wherein said rear wing segment comprises a wingtip which curves backand couples to a rearward propulsor pylon or propulsor nacelle to forman auxiliary pitch control surface.
 11. The aerial vehicle of claim 8wherein said rear wing segment comprises a wingtip which curves back andcouples to a rearward propulsor pylon or propulsor nacelle to form anauxiliary stabilizing surface.
 12. The aerial vehicle of claim 7 whereinsaid aerial vehicle further comprises an auxiliary pitch control orstabilizing surface, said auxiliary pitch control surface joining two ormore propulsor pylons or propulsor nacelles with an aerodynamic surface.13. The aerial vehicle of claim 8 wherein said aerial vehicle furthercomprises an auxiliary pitch control or stabilizing surface, saidauxiliary pitch control surface joining two or more propulsor pylons orpropulsor nacelles with an aerodynamic surface.
 14. The aerial vehicleof claim 7 wherein a trailing edge of one or more pylons forms anaerodynamic control surface that may be deflected to provide lateralcontrol authority.
 15. The aerial vehicle of claim 8 wherein a trailingedge of one or more pylons forms an aerodynamic control surface that maybe deflected to provide lateral control authority.
 16. The aerialvehicle of claim 1 wherein said rear wing segment comprises a wingtipwhich forms a C-shaped section.
 17. The aerial vehicle of claim 16wherein the C-shaped wingtip section includes aerodynamic controlsurfaces.
 18. The aerial vehicle of claim 2 wherein said rear wingsegment comprises a wingtip which forms a C-shaped section.
 19. Theaerial vehicle of claim 18 wherein the C-shaped wingtip section includesaerodynamic control surfaces.
 20. The aerial vehicle of claim 3 whereinsaid rear wing segment comprises a wingtip which forms a C-shapedsection.
 21. The aerial vehicle of claim 20 wherein the C-shaped wingtipsection includes aerodynamic control surfaces.
 22. An aerial vehicle,said aerial vehicle comprising an oblique flying wing, said obliqueflying wing comprising: a center wing segment; a forward wing segment,said forward wing segment coupled to a first end of said center segment,said forward wing segment comprising a leading edge and a trailing edge,wherein the spanwise average of the quarter chord of said forward wingsegment is swept more than 10 degrees differently than the spanwiseaverage of the quarter chord of the center wing segment; and a rear wingsegment, said rear wing segment coupled to a second end of said centersegment, said rear wing segment comprising a leading edge and a trailingedge, wherein the spanwise average of the quarter chord of said rearwing segment is swept more than 10 degrees differently than saidspanwise average of the quarter chord of the center wing segment,wherein said center wing segment is substantially thicker than saidforward wing segment and said rear wing segment, and wherein saidforward wing segment is forward swept in the range of 15 to 35 degrees,and wherein said middle wing segment is swept in the range of 35 to 65degrees, and wherein said rear wing segment is rearward swept in therange of 25 to 45 degrees, while in a cruise configuration.